Weighing dispenser

ABSTRACT

Apparatus for dispensing measured quantities of granular or other flowable material, including a hopper having a discharge outlet controlled by a valve member biased to outlet closing position, a pivoted latch for holding the valve member in outletopening position but biased to release the valve member, and a tiltable pan for receiving material discharged through the hopper outlet. A pair of mutually attracting magnetic elements respectively carried by the latch and by the pan in spaced relation to each other exert a force that both opposes tilting of the pan and holds the latch in engagement with the valve member after the valve member is moved to outlet-opening position. When the weight of material accumulating on the pan overcomes this force, the pan tips, dispensing the material, and the biased latch is released, allowing the valve member to close the hopper outlet, ending the discharge. A counterweight thereafter returns the pan to its material-receiving position. The weight of material that will tilt the pan may be selected by adjusting the relative spacing of the magnetic elements in a direction perpendicular to the direction in which the element carried by the pan moves when the pan tilts.

United States Patent [19] Weber [451 Mar. 12, 1974 WEIGHING DISPENSER[76] Inventor: Robert L. Weber, Box 217, New

Canaan, Conn. 06840 [22] Filed: May 18, 1972 [21] Appl. No.: 254,618

[52] US. Cl 222/55, 177/114, l77/DIG. 5 [51] Int. Cl G01g 13/00 [58]Field of Search 222/55, 56, 77, 58, 364,

222/450, 505, 508; 177/110, 114, 115, DIG. 5, 184, 185, 187, 188, 189;214/182, 17 C; 292/2515; 24/201 B Primary Examiner-Robert B. ReevesAssistant Examiner-Francis J. Bartuska Attorney, Agent, or Firm-Cooper,Dunham, Clark, Griffin & Moran [57] ABSTRACT Apparatus for dispensingmeasured quantities of granular or other fiowable material, including ahopper having a discharge outlet controlled by a valve member biased tooutlet closing position, a pivoted latch for holding the valve member inoutlet-opening position but biased to release the valve member, and atiltable pan for receiving material discharged through the hopperoutlet. A pair of mutually attracting magnetic elements respectivelycarried by the latch and by the pan in spaced relation to each otherexert a force that both opposes tilting of the pan and holds the latchin engagement with the valve member after the valve member is moved tooutlet-opening position. When the weight of material accumulating on thepan overcomes this force, the pan tips, dispensing the material, and thebiased latch is released, allowing the valve member to close the hopperoutlet, ending the discharge. A counterweight thereafter returns the panto its material-receiving position. The weight of material that willtilt the pan may be selected by adjusting the relative spacing of themagnetic elements in a direction perpendicular to the direction in whichthe element carried by the pan moves when the pan tilts.

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WEIGHING DISPENSER BACKGROUND OF THE INVENTION This invention relates toapparatus for metering and dispensing predetermined quantities offlowable materials. The term flowable materials," as employed herein, isintended to embrace granular, pulverulent, powdered, and other dividedor particulate solid materials as well as liquids, slurries, and thelike, i.e., materials in general, whether solid or liquid, characterizedby an ability to advance in bulk by gravity feed in a substantiallycontinuous and free-flowing manner.

Many types of material-handling operations involve the metering anddispensing of successive discrete quantities of flowable material from abulk supply thereof. Commonly, in such operations, it is desired thatthe successive quantities be as nearly identical as possible in weight,each quantity conforming closely to a preselected value of weight. Itmay also be desirable from time to time, in dispensing successivemetered quantities of material from a bulk supply, or in the course ofusing a given dispensing apparatus, to alter the predetermined weightvalue so as to increase or decrease the size of the individual dispensedquantities. Other customary desired properties of metering or dispensingapparatus for flowable materials include ease and reliability ofoperation.

Simply to way of illustration, one specific example of an operation towhich the foregoing considerations are pertinent is the dispensing ofcoffee, i.e., coffee in divided, granular, particulate, or otherflowable solid form, such as (by way of example) coffee beans, groundcoffee, or powdered coffee. Especially in commercial establishments, itis desirable to dispense, from a bulk supply of coffee, successivecarefully metered, substantially equal quantities of coffee. Each ofthese quantities should conform closely to a preselected weight value,but from time to time it may be desired to adjust that value so as tometer out larger or smaller quantities of coffee. While highrepeatability of operation is desired in coffee-dispensing apparatus(i.e., close conformity of each of successive quantities to thepredetermined value), coffee dispensing operations are frequentlyperformed by relatively untrained personnel, and it is thereforenecessary to provide a dispensing apparatus that can be readily operatedby persons having little skill or experience.

SUMMARY OF THE INVENTION An object of the present invention is toprovide new and improved apparatus for weighing and dispensingsuccessive quantities of flowable material, characterized byadvantageous ease and high accuracy or repeatability of operation.

A further object is to provide such apparatus in which the quantity tobe metered can readily be adjusted in a sensitive, accurate manner withminimal danger of disrupted operation owing to misadjustment of theapparatus.

To these and other ends, the present invention broadly contemplates theprovision of flowable material metering and dispensing apparatus of thetype including a pan for receiving flowable material to be dis-' pensed,means for supporting the pan for movement to and from amaterial-receiving position in response to absence or presence of weighton the pan, means for retaining the pan in such position with a forcethat is overcome (releasing the pan for movement) by a preselectedweight of material on the pan, and means for dispensing flowablematerial onto the pan when the pan is in such position, includingcontrol means for starting and stopping the discharge of material. Inaccordance with the present invention, the control means includes amovable control member for stopping discharge, normally urged to adischarge-stopping position but movable to permit discharge, and theretaining means includes first and second mutually attracting magneticelements respectively carried by the pan and by the control member andcooperating to exert a force that opposes movement of the pan away fromits materialreceiving position while simultaneously holding the controlmember away from its discharge-stopping position. The two magneticelements are spaced apart by a 7 distance which is at a minimum when thepan is in its material-receiving position and which increases as the pan(carrying one of those elements) moves from such position.

It will be understood that the term mutually attracting magneticelements is employed herein to designate a pair of elements of suchcharacter and disposition that there exists a net attractive forcebetween them. Thus, at least one of the pair of elements is either apermanent magnet or a continuously energized electromagnet; The otherelement is preferably an armature, but may alternatively be a permanentmagnet (or electromagnet) so oriented that opposite poles of the twoelements face each other.

In the operation of this device, with the pan in discharge-receivingposition, the control means operated to permit discharge of materialonto the pan, and the control member held by magnetic force away fromits discharge-stopping position, the flowable material to be metered anddispensed is discharged continuously onto the pan. When a sufficientweight of the material has accumulated on the pan, the magnetic forcethat opposes movement of the pan is overcome, and the pan moves awayfrom its initial position under the weight of material, e.g. tilting todispense the material through a subjaccnt'funnel or passage. As the panthus begins to move, the effective air gap between the aforementionedmagnetic elements increases, with concomitant very rapid decrease in theforce exerted between the elements. Consequently the control member isreleased for movement to discharge-stopping position, and the dischargeof material is arrested. counterweight means or the like may be providedfor restoring the pan to its initial material-receiving position for thenext cycle of operation.

As a further particular feature of the invention, the magnetic elementsmay be so arranged that when the pan is in its material-receivingposition, the two elements are spaced apart along a line substantiallyperpendicular to the direction in which the magnetic element carried bythe pan moves when the pan begins to descend from the initial position;and at least one of the two magnetic elements may be mounted forpositional adjustment along this line. Such adjustment varies the airgap between the magnetic elements when the pan is at the initialposition, and hence varies the magnitude of the force then exertedbetween them. Since the magnitude of the weight of discharged materialthat will cause the pan to move is dependent on the force opposing suchmovement, this adjusting feature enables selection of the weight of thedispensed quantities of material. At the same time, the orientation ofthe direction of adjustment in relation to the direction of movement ofthe magnetic element carried by the pan facilitates avoidance ofundesired contact between the two magnetic elements in the event ofmisadjustment.

In specific embodiments of the apparatus, the discharge means includes adownwardly opening hopper for containing a bulk supply of flowablematerial, and the control means includes a valve member biased toward aposition closing the hopper outlet but movable to open that outlet. Thecontrol means further includes, as the aforementioned control member, apivoted latch positionable to engage the valve member when the valve isin outlet-opening position, but biased to release the valve for movementto outlet-closing position.

In such embodiment, the pan and a counterweight are carried on a balancebeam which is pivotally mounted to move about a horizontal axisintermediate the counterweight and pan. The counterweight opposesdownward tipping of the pan from a horizontal position beneath thehopper outlet, but the weight of accumulating material dischargedthrough the outlet onto the pan tends to pivot the beam downwardly,tilting the pan to dispense the material.

The magnetic elements are respectively carried by the latch and pan soas to be in facing, more or less closely spaced relation when the pan ishorizontally disposed. One of these elements is mounted for adjustmenttoward and away from the other. The force exerted between the magneticelements opposes tilting of the pan either upwardly or downwardly, andalso holds the latch in engagement with the valve member for restrainingthe valve member in the outlet-opening position.

When the valve member is moved to open position (e.g. by means of ahandle), material descends from the hopper by gravity onto the pan. Theweight of material that will cause the pan to tilt is determined by theforce exerted by the magnetic elements. Once this predetermined weightis reached, the pan tilts, the latch is released, the valve membercloses the hopper outlet to terminate discharge, and the meteredquantity of material is dispensed from the tilted pan. The counterweightthen causes the pan to swing back upwardly to its initial, horizontalposition where it is held by the magnetic elements for the next cycle.Suitable damping means may be associated with the balance beam forpreventing oscillation of the pan especially in its return motion.

Further features and advantages of the invention will be apparent fromthe detailed description hereinbelow set forth, together with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational sectionalview of apparatus for dispensing ground coffee or the like, embodyingthe present invention in a particular form;

FIG. 2 is a fragmentary view similar to FIG. I, illustrating a firststage in the metering and dispensing operation of the apparatus of FIG.1;

FIG. 3 is a view similar to FIG. 2 illustrating a subsequent stage inthe same cycle of operation;

FIG. 4 is an external side elevational view of the FIG. 1 apparatus,taken along the line 4--4 of FIG. 1;

FIG. 5 is a fragmentary elevational view taken along the line 55 of FIG.4

FIG. 5a is an enlarged fragmentary detailed view of certain elementsshown in FIG. 5;

FIG. 5b is a further enlarged perspective view of an end of theactuating rod shown in FIG. 5;

FIG. 6 is a fragmentary sectional plan view of the apparatus of FIG. 1taken along the line 6-6 of FIG. 1;

FIG. 7 is a fragmentary plan view taken along the line 77 of FIG. 1;

FIG. 8 is a fragmentary sectional elevational view taken along the line8-8 of FIG. 1;

FIG. 9 is a side elevational sectional view of a modified form ofapparatus, embodying the present invention, for dispensing ground coffeeor the like;

FIG. 10 is a fragmentary view similar to FIG. 9, showing an intermediatestage in the metering operation of the apparatus;

FIG. 11 is a fragmentary view taken along the line llll of FIG. 10;

FIG. 12 is an enlarged fragmentary detailed view taken along the linel2-12 of FIG. 10;

FIG. 13 is an enlarged fragmentary detailed view taken along the linel3-l3 of FIG. 10; 9

FIG. 14 is a fragmentary detailed view taken along the line 14-14 ofFIG. 10;

FIG. 15 is a sectional plan view taken along the line 1515 of FIG. 9;

FIG. 16 is a view similar to FIG. 10 but showing a further modificationof the apparatus to provide demand rather than metered operation; and

FIG. 17 is a fragmentary view similar to FIG. 9, showing anothermodification in the apparatus of FIG. 9.

DETAILED DESCRIPTION FIGS. 1 8

The present invention is shown in these figures as embodies in apparatusfor metering and dispensing successive equal quantities of coffee orlike granular or particulate material, in response to successive orrepeated displacements of an actuating rod 2.

The apparatus of FIGS. 1 8 is enclosed within a rigid housing 10 dividedinto upper and lower chambers (respectively designated 11 and 12) by adownwardly tapering frustoconical wall 14. At its lower end, the wall 14defines a circular discharge opening or outlet 15. The chamber 11,enclosed by wall 14 and the upper portions of the housing 10, thusconstitutes a hopper for containing a bulk supply 16 of flowable solidmaterial such as coffee. The top of the hopper may be closed by aremovable lid 17.

The outlet 15 is normally closed by a manually operable valve comprisinga guillotine member 20 disposed below the wall I4 for movement in acurved path about a horizontal axis, into and out of engagement with thedownwardly projecting circular lip 15a of the outlet 15. As shown, theguillotine member is a rigid plate, curved on the same radius as itspath of movement, and dimensioned to close the outlet 15 completely whenin its lower position. The lip 15a, engaging the upper surface of member20, may be formed with a knife edge to prevent clogging.

As best seen in FIGS. 7 and 8, the guillotine member 20 includes a pairof laterally and upwardly projecting arms 22 which are pivotally securedto side wall portions of the housing 10 (externally of wall 14) so as tosupport the guillotine for movement along the aforementioned curvedpath. One of the arms 22 is connected to a resiliently flexible leversuch as a trip wire 23 that projects outside the housing for angularmovement in a plane generally parallel to the adjacent housing wall,between lower and upper limiting positions respectively defined by stoppins 23a and 23b (FIGS. 5 and 5a) mounted in the housing wall to engageand arrest the trip wire. As hereinafter further explained, this tripwire 23 is movable by the actuating rod 2 (from lower to upper position)to effect movement of the guillotine 20 from closed to open position.

As seen in outlet-closing position (FIGS. 1 and 3), the guillotineextends beneath the outlet and further includes an elongated portion 24extending upwardly therefrom along the same curved path, beneath thewall 14. In such closed position, the leading edge of the guillotinemember abuts a small resilient bumper 26 fixedly mounted on a short wallportion 27 of the housing structure adjacent the outlet 15. When theguillotine is swung upwardly (by means of trip wire 23) to the openposition shown in FIG. 2, its trailing edge may abut a similar bumper 28mounted at the junction of wall 14 with housing 10. As thus displaced toopen position, the guillotine 20 clears the outlet 15, permitting thematerial 16 to flow freely through the outlet from the hopper 11, underthe force of gravity.

The extension 24 of the guillotine member, together with the illustrateddisposition of the pivotal mounting for the guillotine member, causesthe member to be gravity-biased toward its closed position; i.e., if themember 20 is moved to the open position shown in FIG. 2 and released, itreturns immediately by gravity to the closed position of FIGS. 1 and 3.The weight of extension 24 is selected, in relation to the nature of thematerial being dispensed, to insure that return movement of theguillotine member to outlet-closing position will be effectedsufficiently forcefully to overcome the resistance of the materialflowing downwardly through outlet 15.

In order to retain the guillotine member in the outletopening position,a sear or latch member 30 is pivotally secured to fixed wall portions 31of the housing structure by a pivot shaft 32 (FIG. 7) for angulardisplacement about a horizontal axis, below the curved path of theguillotine member. It will be understood that for convenience ofexpression, the terms pivot and pivotally are used herein to refer toangular displacement about a fixed axis, and to designate mountings (ofapparatus elements) permitting such motion, whether the mountings arepivots in a conventional sense or are other structures such as rotatableshafts or fixed shafts on which elements are journalled for such motion.The latch 30 includes a short transverse arm 311a which extends inwardly(toward outlet 15) from pivot 32 and terminates in an upwardlyprojecting tooth 30b disposed for insertion in a detent opening 34 inthe guillotine member, i.e., when that member is swung to open position(FIG. 2), to engage and hold the guillotine member against returnmovement to outlet-closing position. Latch 30 also includes a furtherarm 300 formed integrally with and extending downwardly from the arm 30abetween spaced stop pins 37 and 38 which are mounted in the wallportions 31 to limit the angular travel of the latch.

A balance beam 40, disposed in downwardly spaced relation to the hopperwall 14, is mounted for movement about a horizontal axis by means of apivot shaft 41 journalled in inwardly projecting portions 42 of thehousing wall structure. The beam includes a scale arm 40a carrying ashallow tray or pan 44 and a counterweight arm 40b respectively disposedon opposite sides of shaft 41 so that when the beam is in the horizontalposition shown in FIGS. 1 and 2, the pan 44 is located directly beneathand aligned with the hopper outlet 15 for receiving material dischargedthrough the outlet. The counterweight arm 40b overbalances the arm 40aand the empty pan 44 slightly so as to restore the beam toward thehorizontal after an angular displacement of the beam clockwise from theposition shown in FIG. 1. Magnetic elements 57 and 58 are then effectiveto hold the beam 40 horizontal, as explained more fully below.

When the material 16 is delivered to the pan 44, the weight of thatmaterial tends to cause clockwise pivotal motion of the beam(overbalancing the counterweight), tilting the pan downwardly so thatthe material falls therefrom into the lower portion of the housing 10,as shown in FIG. 3. This lower housing portion may, as shown, be formedto constitute a downwardly tapering funnel 46 for dispensing the fallingmaterial through a passage 47 at the lower extremity of the apparatus.

The counterweight arm 40b is shown as wedgeshaped with a curved orarcuate outer periphery 49 (of uniform radius) concentric with pivot 41,and carries an arcuate retaining member 50 having a major extentconforming in curvature with but spaced outwardly from the periphery 49.The arm 40b is of relatively light material, e.g. plastic, and theretaining member 50 is of relatively heavy material, e.g. steel, so thatthe member 50 constitutes the principal counterweight. The member 50 hasits ends bent in the form of spring fingers 500, which engage recessesin the arm 40b, so that the member 50 may be readily removed andreplaced by a lighter or heavier member, as required by the quantity tobe dispensed by the apparatus. Periphery 49 and retaining member 50cooperatively define a curved track (having closed ends) within whichmay be disposed a roller 52, joumalled (for rotation about a horizontalaxis) at the end of the crank arm on a crankshaft 53 (FIG. 6) that ispivotally mounted on the housing structure, and frictionally engagingthe periphery 49 of arm 40b so that the roller rotates aobut ahorizontal axis. A pair of governor blades 54 are connected to theroller 52 for rotation therewith. The roller 52 and blades 54 rotate asthe beam is restored to horizontal position by the action ofcounterweight air resistance to rotation of the blades, transmitted tothe beam by the frictional engagement of the roller 52 therewith, servesa damping function that prevents undesired overtravel and oscillation ofthe beam such as might otherwise occur during its return to horizontalposition.

The horizontal axis 53a about which the crankshaft 53 rotates is spacedfrom the pivot shaft 41 of the balance beam 40 by a distance which isless than the sum of the radius of the periphery 49 and the length ofthe crank arm of crankshaft 53, at the end of which arm the roller 52 isjournalled. Furthermore, the roller 52 is above the line between theaxis 53a, and the pivot shaft 41 (i.e., the axis of roller 52 lies abovethe plane defined by the horizontal axes of beam pivot shaft 41 andcrankshaft 53). Because of this dimensional relationship, when thebalance beam 40 moves clockwise from the position of FIG. 2 to theposition of FIG. 3, the frictional engagement between periphery 49 androller 52 lifts the crank arm upward, decreasing that frictionalengagement, so that the roller 52 slides in the space provided betweemmember 50 and periphery 49, and rotates very little, if at all, with aminimal retarding effeet on the motion of the balance beam 40.

On the other hand, when the balance beam moves counterclockwise from theposition of FIG. 3 to that of FIG. 2, the frictional engagement ofperiphery A9 and roller 52 tends to move the cranksahft 53 clockwise onits pivot, thereby forcing the roller 52 more tightly against periphery49 and rotating the blades 54 to produce a maximum damping action on themotion of balance beam 40.

As a particular feature of the invention, for metering and dispensingflowable solid material, the pan 44 has a downwardly tapering conicalshape with side walls sloping at an angle of between about 3 and about10 to the horizontal when the beam 40 is in its horizontal position.This slope of the pan surface is advantageous for optimum dumping ofaccumulated material from the pan when the pan is tilted downwardly, andfor optimum piling of the material, without spillage, when the pan isfilling.

In accordance with the invention, a pair of magnetic elements 57 and 58are respectively carried by the latch 30 and the beam 41th in facingrelation to each other. The latch arm 300 extends downwardly to thelevel at which scale arm 40a is located when the beam 40 is inhorizontal position so as to be in horizontally spaced relation to theextremity of the scale arm 50a. Magnetic element 57 is secured to ascrew 60 which is threadedly mounted in the lower extremity of the latcharm 306 (with element 57 facing toward the beam), while magnetic element58 is mounted in the beam end facing element 5'7. The disposition ofthese elements is such that, when the beam is in its horizontal position(FIG. ll), the elements 57 and 558 face each other across a small airgap 62. The dimension of this air gap may be adjusted by turning thescrew 6th so as to move element 5'7 toward or away from element 58, butthe adjustment is limited, eg by deforming a thread on the screw 6th, sothat the air gap is maintained at all times.

As shown, element 57 is a magnet, while element 58 is an armature onwhich 57 exerts an attractive force which is a maximum when the air gapis shortest, i.e., when the pan 44 is in the horizontal position. Whileelement 57 may be a continously energized electromagnet, it is presentlypreferred (for the sake of convenience and simplicity) that element 57be a permanent magnet. Alternatively, the elements 57 and 58 may bereverse, so that 57 is an armature and 58 a magnet, or both elements maybe magnets with facing poles of opposite polarities.

As will now be understood, the force exerted by magnet 57 on armature58, when the beam 4% is in its horizontal position shown in FIG. ll,holds the beam horizontal. When the pan is empty, the counterweight arm40b and counterweight 50 overbalance the scale arm 40a slightly, andthis overbalance is counteracted by the magnetic elements 57 and 58. Asthe pan 44 starts to till, the balance beam becomes overbalanced in theopposite direction, and the magnetic elements 57 and 58 are theneffective to hold the beam horizontal until the weight of material onthe pan exceeds a predetermined value, dependnet on the strength of themagnetic elements 57 and 58 and the length of the air gap between them.At the same time, this force of elements 57 and 58 also urges thepivoted latch 30 in a clockwise direction as seen in FIG. il, i.e.,toward the inner stop pin 37. As will be apparent from FIG. 2, when thelatch 30 is at the limit of its clockwise pivotal movement (engaging pin37), the latch tooth 30b is in a position to be received within thedetent opening 34 of the guillotine member 20 and thus to hold theguillotine member in the above-described outlet-opening position. Thelatch 30 is so balanced on its pivot shaft that (in the absence of thedescribed magnetic force) it is urged by gravity in a counterclockwisedirection from the position shown in FIG. 1, to an outer limitingposition in which it engages pin 38; when the latch is disposed at thisouter limiting position, tooth 30b is located beneath (and clear of) thepath of guillotine movement. The guillotine extension 24 may bear, onits upper surface, a wear plate 24a removably secured to the guillotineas by screws 24b and having a lip extending over the rim of opening 34that is engaged by tooth 30b, for protecting that rim.

As shown in FIG. 4, the dispensing passage 47 projects downwardly belowthe bottom of the housing 10 so as to be receivable within a manuallyheld coffee cup K or the like. The rod 2 has its lower end received, forguided vertical movement, within a vertical slot 47a formed in the wallof passage 47. From slot 47a, a horizontal arm portion 2a of rod 2extends below the housing 10 to a locality beneath the position of tripwire 23 adjacent a vertical wall of the housing; at that point, the rodis bent upwardly, forming a vertical leg 2b that projects upwardlythrough a vertical guide sleeve 10a provided on the outer surface of thelast-mentioned housing wall beneath the trip wire 23. Above sleeve 10a,the rod is bent again to form a further horizontal arm 20 (FIG. 5) thatextends in parallel relation to the adjacent housing wall and terminatesin a short, upwardly projecting vertical leg 2d having a transverselyprojecting upper end 2e (FIG. 5b) positioned to engage the free end ofthe trip wire 23. Rod 2 is movable vertically between the lower positionshown in FIGS. 4 and 5, at which the upper rod end 2e is disposedimmediately below the free end of trip wire 23 (i.e., when the trip wireis at its lower position, engaging stop pin 23a), and an upper positionat which the upper rod end 2e reaches the position shown at 2e (FlG.5a).

The described vertical movement of rod 2 is effected by manually movinga cup K (FIG. upwardly over passage 47 so that the cup lip engages, andpushes upwardly, the horizontal arm 2a of the rod. As the rod begins torise, its upper end 2e engages and pushes upwardly against the trip wire23, causing the trip wire to pivot upwardly from its lower position(engaging pin 23a) to its upper position, at which the trip wire isarrested by pin 23a. This upward movement of the trip wire swings theguillotine 20 from outlet-closing position to outlet-opening position,as described above.

The upper most position 2e of rod end 2e is, as indicated in FIG. 5a,slightly above the position at which the trip wire 23 comes intoengagement with the upper stop pin 23b. As shown in FIG. 5b, rod end 2eis cut away to provide a half-round configuration with a flat sidefacing the trip wire 23. This shape of end 2e permits the free end ofthe trip wire to be released from engagement with rod end 2e as the rodend continues to move upwardly (to position 2e) after the trip wire hasengaged pin 231;. In other words, during the terminal stage of upwardmovement of rod end 22, the free end of the resilient trip were 23flexes progressively, until (as permitted by the cutaway configurationof end 2e) it is released, and springs downwardly away from end 2e,which is now positioned above the trip wire. Consequently the trip wireand guillotine are free to fall to outlet-closing position upon releaseof latch 30, without interference with rod end 2e, even though cup K isstill held in a position that maintains rod end 2e at the upper position2e. When the cup is thereafter removed, the arm 2 drops, with sufficientforce so that (again owing to the resiliency of trip wire 23, and thecutaway configuration of the rod end 2e), the end 2e descends past thefree end of the trip wire to its initial position beneath the trip wire.

Means for retarding upward movement of rod 2 are also provided in theapparatus of FIGS. 1 8, to prevent metering errors that might otherwiseresult if a cup K were moved rapidly upwardly and downwardly, moving theguillotine to outlet-opening position and then releasing it before thelatch 34) could move to hold the guillotine in that open position. Thisretarding means is illustrated in FIG. 4 as comprising a dashpot 65including a downwardly opening, axially vertical cylinder 66 formed inthe lower portion of the housing an upwardly opening cup-shaped piston67 disposed for axial movement in cylinder an and connected to rod arm2a by a lug 67a; and a vaned valve member 68, loosely contained withinpiston 67 and seating in an aperture 68a in the bottom of the piston.When the rod 2 is pushed upwardly, piston 67 is forced upwardly intocylinder 66 while valve 63 closes aperture 68a, so that air in thecylinder is compressed, resisting (and hence retarding) the upwaredmovement of the rod sufficiently to permit latch 30 to catch and holdthe guillotine member in open position. Upon release of the rod, thepiston 67 is free to fall, and any negative pressure differentialbetween the cylinder and ambient atmosphere (such as might tend toretard downward movement of the piston) is relieved by movement of valve68 relative to the piston, opening aperture 68a.

The foregoing arrangement of rod 2, trip wire 23, and dashpot 65, aswill now be seen, is designed to enable the apparatus to provideaccurate metering operation despite variations in manual actuation,i.e., regardless of whether the cup K is held in an upper position ormoved rapidly up and down. Accordingly, the described apparatus affordsdesirable freedom from human error, an advantage which is especiallyimportant for operations (such as coffee dispensing) commonly performedby relatively unskilled personnel.

The operation of the described apparatus may now be readily explained. Asupply lid of bulk tlowable solid material such as coffee is initiallycharged to the hopper ill with the lid 17 removed. A receptacle such ascup K for receiving a metered quantity of the material is placed beneaththe downwardly opening dispensing passage 47. At this time, the beam 40is in the horizontal position shown in FIG. ll, held by the force ofmagnet 57 exerted on armature 53. The guillotine member is in the closedposition, preventing discharge of material from hopper 11 through outiet15. The latch 30 is urged clockwise as seen in H6. 1, by theaforementioned magnetic force, but is arrested short of its clock wiselimit of travel by engagement of the tooth 30b with the lower surface ofthe guillotine extension 24.

To dispense a metered quantity of the material into the receptacle, cupK is raised, moving rod 2 (and hence trip wire 23) upwardly to swing theguillotine to open position. As the guillotine detent opening 34 comesinto register with the latch tooth 30b, the force exerted by magnet 57on armature 58 pivots the latch clockwise so that the tooth 30b isreceived in the detent opening 34, holding the guillotine member in itsoutletopening position, and allowing magnet 57 to swing slightly closerto armature 58.

With the outlet thus open, as seen in FIG. 2, granular material isdischarged freely therethrough onto the pan 44. The combined forces ofcounterweight arm 40b, counterweight 50 and magnetic elements 57 and 58retain the beam 40 in horizontal position, despite the growing weight ofmaterial on the pan. However, when a sufficient weight of material hasaccumulated on the pan to overcome the combined effect of thecounterweight and magnetic forces, the pan 44 begins to tilt, i.e., thebeam 40 begins to pivot in clockwise direction as seen in FIG. 3.

The clockwise pivotal motion of the beam carries the armature 58progressively further away from the magnet 57. As the space betweenmagnet and armature thus increases, the force exerted by the magnet onthe armature decreases in accordance with the inverse square law,producing rapid acceleration of beam pivotal movement, and concomitantlyreleasing the latch 30 for counterclockwise pivotal movement by gravityinto engagement with pin 38. This movement of the released latch carriesthe tooth 30b downwardly out of engagement with the guillotine, freeingthe guillotine to drop back to outlet-closing position, and thereby tostop the discharge of material through outlet 15. In other words, as thepan tilts downwardly, the discharge of material is stopped. Thecontinuing downward tilting of the pan dumps the accumulated materialinto the funnel 46, whence it falls through passage 47 into theaforementioned receptacle. It should be noted that FIG. 3 illustratesthe extreme downward limit of tilting movement of the pan; ordinarilythe pan does not travel so far, but instead the accumulated materialfalls from the pan when the pan has moved thorugh a somewhat lesserangle from the horizontal, i.e., when the pan is at a position displacedcounterclockwise from that shown in FIG. 3.

Once the accumulated material has fallen from the pan, the beam isrestored to its initial horizontal position by the counterweight ann 40band magnetic elements 57 and 58; i.e., the counterweight causes the beamto swing in a counterclockwise direction (as viewed in FIGS. 1 3), andthe attractive force between elements 57 and 58 arrests thiscounterclockwise movement as the pan reaches its initial, horizontalposition. At the same time, the attraction between elements 57 and 58swings the latch back into a position for engaging detent opening 34 ofguillotine 20 when the guillotine valve is re-opened. As sonn as a newcup K is placed beneath passage 47, a further metered quantity of thematerial 16 can be dispensed by the apparatus in the same manner asdescribed above.

Since the magnetic component of the force that acts on beam 40 to retainthe pan in horizontal position is related to the distance between magnet57 and annature 58 when the beam is horizontally disposed, themagnet-armature spacing determines (for any constant weight of thecounterweight member 50) the weight of material which will overcome thepanretaining force and cause tilting of the pan and closure of theoutlet 15 by guillotine 20.. In other words, the spacing between magnet57 and armature d predetermines the weight of each individual meteredquantity of material dispensed by the apparatus. It is found that for agiven relative spacing of the magnetic elements 57 and 58, the operationof the illustrated apparatus is highly repeatable; i.e., successivemetered and disposed quantities of material are highly uniform inweight.

To change the weight of such metered quantity, the magnet-armaturespacing may be adjusted by turning the threaded mounting of magnet 57 inlatch arm 30c. Once that spacing is adjusted, the apparatus willdispense metered quantities of material having a new (larger or smaller)value as desired. To facilitate adjustment of magnet position, the outerend of post 60 may be slotted, and may be accessible (for turning, as bymeans of a screwdriver) through an opening 64 in the adjacent wall ofthe housing Ml When the loaded pan begins to tilt, the outlet is notinstantly closed, but instead remains open (with continuing discharge ofmaterial therethrough) during the short interval required for theguillotine to fall back to outlet-closing position. The total weight ofmaterial in each metered quantity dispensed by the apparatus is thus thesum of the weight that is deposited on the pan before the pan begins totilt, and the weight of the increment of material discharged through theoutlet 15 between the time when the pan begins to tilt and the time whenthe guillotine fully closes the outlet. As stated, the weight ofmaterial required to tilt the pan is determined by the attractive forcebetween elements 57 and 58. The rate of closing of the guillotinedepends on the size of the granules or particles flowing through theoutlet, being slower when the particles are large than when they aresmall; it is found that for a given particle size range and density, theweight of the increment of material discharged through the outlet duringthe guillotine-closing period is substantially constant, and hence doesnot adversely affect the metering accuracy or weight-selectingadjustability of the apparatus.

It will be noted that when the beam is horizontally disposed and theoutlet H5 opened, the spacing between the magnet and armature is at aminimum, and these elements are then spaced along a horizontal line,i.e., a line perpendicular to the (vertically downward) direction ofinitial movement of the armature when the pan begins to tilt; thearmature follows an arcuate path, but the instantaneous direction of itsmotion from the horizontal is, of course, tangent to that path. Theadjustment of the air gap 62 is effected by movement of the magnet 57along this horizontal line, i.e., in a direction perpendicular to thedirection of armature motion. Owing to this relative orientation of thedirection of magnet adjustment and the direction of armature motion, theadjusting mechanism can readily be constructed so as to preventadjustment of the magnet into a position at which the magnet contactsthe armature, which would be highly undesirable.

FIGS. 9 115 This embodiment includes a housing 70 having an upperportion shaped to constitute a hopper 72 for bulk solid flowablematerial, with a hinged lid '73 for the hopper. The metered material isdicharged from the hopper by gravity through a downwardly opening outlet74 onto a. shallow pan 75 which may have the same surface configurationas the pan 44 of the FIG. 1 apparatus. A beam 77, pivotally mounted at78 on portions of the housing structure for angular displacement about ahorizontal axis, carries the pan and a bifurcate counterweight structure80 on opposite sides of its axis of pivotal movement. The counterweightstructure 80 includes a pair of arms 80a on which are threaded weights80b, and is arranged to maintain the pan in a horizontal positiondirectly beneath and aligned with hopper outlet 74, and to restore thepan to such position when the pan is tilted downwardly by weight ofmaterial delivered thereto from the hopper. A spring element 81, fixedlymounted in relation to the beam, has free lower end portions 81apositioned to engage the counterweight assembly 80 in the event ofcounterclockwise overtravel of the beam, for inhibiting oscillation ofthe beam as the pan is restored to horizontal position.

Discharge of material through the hopper outlet is controlled by a valvemember 82 which comprises a horizontal slide, i.e., a flat rigid platesupported between upper and lower rollers 84 for horizontal movementbetween a position (shown in FIG. 9) at which the slide completelycloses outlet 74, and a position (shown in FIG. 10) at which an aperture86 in slide 82 is in register with outlet 74. A pair of biasing springs88, under tension between the slide and a wall portion of the housing,urge the slide toward its outlet-closing position (the left-hand limitof its path of travel, as seen in FIG. 9). When the slide is moved tothe outlet-opening position, at which aperture 86 is in register withoutlet 74 so that material from the hopper can fall freely through theoutlet and aperture, the slide is at the righthand limit of its path oftravel as seen in FIG. 10.

A latch 90, mounted on portions of the housing structure by a pivotshaft 91 for pivotal motion about a horizontal axis, is provided forholding the slide 82 in open position against the biasing force ofspring 88. Latch carries, on a short transverse arm 90a, an upwardlyprojecting tooth 90b arranged for insertion within a detent opening 94of slide 82, i.e., when the slide is in open position. The latch 90,which is generally similar in structure and function to the latch 30 ofthe FIG. 1 apparatus, also includes a downwardly extending arm 99c.

Also as in the apparatus of FIGS. ll 8, the latch arm 90c and theadjacent extremity of beam 77 (carrying pan 75) respectively bear twomutually attracting magnetic elements 97 and 98. One of these elements(e.g. element 97) is a permanent magnet or a continuously energizedelectromagnet, while the other (e.g. element 98) may be a magnet or anarmature; as shown, both elements 97 and 98 are permanent magnets,oriented so that their respective facing poles are of unlike polarity.The dispostion of the two magnetic elements is such that when the pan 75is in the horizontal, materialreceiving position shown in FIG. 9,elements 97 and 98 are disposed in horizontally spaced, facing relationwith a small air gap 99 between them. The attractive force then exertedbetween magnets 97 and 98 opposes movement of the pan away fromhorizontal position.

The same magnetic force simultaneously urges the pivoted latch 90 in aclockwise direction in FIG. 9, thus urging the latch tooth 90b upwardlyfor insertion in the detent opening 94 of slide 82. Clockwise movementof latch 90 is limited by engagement of the latch arm 90a with the lowersurface of the slide 82. Again as in the case of the latch 30 in theFIG. 1 apparatus, latch 90 is so balanced on its pivotal mounting thatit is normally urged by gravity in a counterclockwise direction thatcarries the tooth 90b downwardly out of engagement with slide 82.counterclockwise movement of the latch is limited by a stop screw 90dadjustably secured to a portion of the housing structure.

The magnitude of the force exerted between magnets 97 and 98 isdetermined by the size of the air gap 99. To permit adjustment of thesize of this air gap, one or both magnets 97 and 98 are threadedlymounted so as to be horizontally adjustably in position.

The left-hand end portion of slide 82 (as seen in FIG. 9) is bentdownwardly and then upwardly to form a stop flange 100 that abuts aninternal wall portion 101 of the housing structure to limit the leftwardtravel of slide 82. I-Iingedly mounted on the under side of theleft-hand end portion of slide 82 is a cam follower frame 103 lightlybiased by a spring 104 into engagement with the under side of the stopflange portion 100 of the slide. In that position, the frame 103 slopesleftwardly and downwardly from the horizontal path of slide 82, but thehinged connection betweenframe 103 and slide 82 permits downward(counterclockwise) pivotal movement of the frame e.g. to the positionindicated by dotted lines at 103 in FIG. 9.

At its leftward extremity, the frame 103 bears a cam follower roller 105adapted to ride on and cooperate with a cam portion 107 of a verticallyextending actuator rod 108 supported for vertical displacement in theleft-hand side of the housing structure 70 as seen in FIG. 9. Rod 108terminates at its lower extremity in a horizontal arm 110 positioned tobe engaged and lifted by the lip of a receptacle such as a coffee cup(not shown). In its initial position, the rod 108 has the position shownin FIG. 9, with the knee-shaped cam portion 107 disposed beneath camfollower 105. The slide 82 is then at its leftward limit of travel. Whemarm 110 is manually lifted, however, earn follower 105 rides on the camportion 107 of the actuator rod 108, over the peak of portion 107,forcing the slide 82 horizontally to the right against the springs 88,until the actuator rod 108 reaches an upper limiting position as shownin FIG. 10. The slide 82 has now moved to the outlet-opening position ofFIG. 10, where it is held by the insertion of latch tooth 90b in thedetent opening 94; and the projection of actuator cam portion 107 haspassed above cam follower 105. Accordingly, if the slide is released bythe latch while the rod 108 is maintained in this upper position (i.e.,while rod am 110 continues to be supported by a coffee cup held beneathit), the cam portion 107 does not interfere with leftward, outletclosingmovement of the slide, since the cam follower 105 rides along thedownwardly and leftwardly sloping lower reach of cam portion 107,pivoting counterclockwise (relative to the slide) if necessary.Subsequent descent of rod 108 to its initial, lower position issimilarly accommodated by counterclockwise pivotal movement of the camfollower 105, without disturbing the outletclosing position of theslide. Thus the metering opera tion of the apparatus is performedindependently of the position of rod 108, once that operation has beeninitiated by upward movement of the rod.

The upward motion of the actuator rod 108 may also operate a tamping oragitating element 114 located within the hopper and bearing horizontaldiscs 115 for promoting uniform downward flow of material from thehopper through outlet 74. As shown in FIG. 9, the upper end of theactuator rod 108 may engage a pivoted arm 110 (as rod 108 moves to thetop of its path of travel), the tamping device being secured to andmoved by arm 116.

With the hopper 72 filled with bulk flowable solid (e.g. granular orparticulate) material, dispensing of a metered quantity of such materialin the apparatus of FIG. 9 is initiated by lifting of the arm 110. Theslide 82 is advanced to the right and latched in outletopening positionas shown in FIG. 10, permitting material from the hopper to flow throughoutlet 74 onto the horizontally positioned pan 75. Upon delivery to thepan of a sufficient weight of material to overcome the combined force ofthe counterweight structure and the magnetic elements 97 and 98, the pantilts downwardly; at the same time, the rapid diminution of magneticforce releases latch to swing in a counterclockwise direction, freeingslide 82 for leftward outletclosing movement under the force of spring88. Thus the delivery of a predetermined weight of material to the pan75 both tilts the pan and closes the hopper outlet. The metered quantityof material (i.e., the weight that causes the pan to tilt plus theweight of the increment of material discharged between the time the panstarts tilting and the time outlet 74 closes) falls onto a sloping lowerportion 120 of the housing 70 which guides the material to a dispensingpassage 122 beneath which there may be positioned a receptacle (notshown) for receiving this metered quantity of material. Passage 122projects downwardly from the housing and is dimensioned to be receivedwithin a coffee cup or the like, while the arm 110 of actuator rod 108extends through a vertical slot 122a in the wall of this passage, sothat positioning of a cup in material-receiving relation to the passagelifts the arm 110 to initiate the metering and dispensing operation ofthe apparatus as described above.

Restoration of the pan to its horizontal position by the counterweightstructure 80 readies the apparatus for repetition of the operation todispense another such metered quantity of material. As in the case ofthe FIG. 1 apparatus, the predetermined weight of each metered quantityof material is related to the spacing between the magnetic elements 97and 98 and may be varied by adjustment of that spacing, or by changingthe size of the counterweights 80b.

FIG. 16

FIG. 10 illustrates a modification that may be made in the apparatus ofFIGS. 9 15 to provide demand rather than metered dispensing. That is tosay, with the structure of FIG. 16, the amount or" material dispensed ineach cycle is controlled manually by the operator rather than beingpredetermined.

Specifically, in FIG. 16, in place of the actuator rod 108 with its camportion 107, there is provided an actuator rod 108' having a cam portion107' which juts out further to the right (as seen in the figure) thandoes the cam portion 107. As illustrated in FIG. 16, when rod 108' ismoved manually upward to the upper limit of its travel, the cam portion107' still engages the cam follower in such manner that the slide 82 ispositively held in outlet-opening position regardless of the position oflatch 90. Thus discharge of material continues as long as the rod 108'is supported manually in an upper position, i.e., until the. rod isreleased for downward movement.

The apparatus is generally similar to that of H08. 9 15 except that thecentrally pivoted arm M6 that holds agitating element 114 is replaced byan arm H6 pivoted at its end in the wall of the housing opposite rod108, so that the agitating element is carried by rod 116' between itspivotal mounting and rod 108..

In the structure of H6. 9, upward movement of rod 108 into engagementwith arm 136 causes downward movement of element 1114, so that the discs115 tamp the supply of material in hopper 72. Owing to the dispositionof element H4 between rod Mp8 and the piv otal mounting of arm lilo inthe structure of FIG. 17, however, upward movement of rod 108 intoengagement with arm 116' produces upward motion of the element 114 sothat the discs lift or fluff the material in the hopper. The selectionof the agitating arrangement to be employed is dependent on theproperties of the material being dispensed.

It is to be understood that the invention is not limited to the featuresand embodiments hereinabove specfically set forth but may be carried outin other ways without departure from its spirit.

l claim:

1. .ln dispensing apparatus, the combination of a. a pan for receivingmaterial to be dispensed;

b. means for supporting the pan for movement to and from amaterial-receiving position in response to absence or presence of weighton the pan; and

c. means for retaining said pan in said position with a force that isovercome, releasing said pan for movement, by a preselected weight ofmaterial on the pan;

wherein the improvement comprises d. said retaining means includingfirst and second mutually attracting magnetic elements respectivelycarried by said pan for movement therewith and connected to saidsupporting means, said elements being spaced apart, when said pan is insaid position, along a line substantially perpendicular to the directionof motion of said first element such that said elements exert on eachother an attractive force opposing movement of said pan from saidposition; and

e. means, mounting at least one of said elements for positionaladjustment toward and away from the other along said line, for varyingthe distance between said elements, thereby to vary the magnitude ofsaid last-mentioned force.

2. ln dispensing apparatus, the combination of a. a pan for receivingflowable material to be dispensed;

b. means for supporting the pan for movement to and from amaterial-receiving position in response to absence or presence of weighton the pan;

c. means for retaining said pan in said position with a force that isovercome, releasing said pan for movement, by a preselected weight ofmaterial on the pan; and

d. means for discharging flowable material onto said pan when said panis in said position, including control means for starting and stoppingdischarge of material;

wherein the improvement comprises e. said control means including amovable control member normally urged to aposition for stoppingdischargebut movable away from discharge stopping position for permittingdischarge; and

f. said retaining means including first and second mutually attractingmagnetic elements respectively carried by said pan and by said controlmember, said elements being spaced apart by a distance which is at afinite minimum value when said pan is in said material-receivingposition and said elements then exerting on each other a predeterminedattractive force simultaneously opposing movement of said pan andholding said control member away from said discharge-stopping position,said predetermined force being overcome by said predetermined weight ofmaterial on said pan such that said pan moves from saidmaterial-receiving position, increasing the distance between saidelements and thereby decreasing the attractive force between saidelements so as to release said control member for movement to saiddischarge-stopping position.

3. Apparatus as defined in claim 2, wherein said magnetic elements arespaced apart, when said pan is in said material-receiving position,along a line substantially perpendicular to the direction of motion ofsaid first element; and further including means, mounting at least oneof said elements for positional adjustment toward and away from theother along said line, for varying the distance between said elements,thereby to vary the magnitude of the attractive force between saidelements.

4. ln dispensing apparatus, the combination of a. a container having adownwardly opening outlet for discharging flowable material;

b. a valve member for closing said outlet biased to outlet-closingposition but displaceable to a position at which said outlet is open;

0. a pivoted latch for engaging and holding said valve member inoutlet-opening position, biased away from engagement with said valvemember;

(1. a pan for receiving flowable material discharged through saidoutlet, pivotally movable upwardly to and downwardly from amaterial-receiving position beneath said outlet in response to absenceand presence of weight on the pan; and

e. means for retaining said pan and latch in positions for discharge ofmaterial through said outlet onto said pan, said retaining means holdingsaid pan in said position with a force that is overcome, releasing saidpan for movement, by a preselected weight of material on the pan, saidretaining means including first and second mutually attracting magneticelements respectively carried by said pan and by said latch, saidelements being spaced apart by a distance which is at a finite minimumvalue when said pan is in said material-receiving position and saidelements then exerting on each other a predetermined attractive forcesimultaneously opposing movement of said pan and holding said latch inposition for engaging said valve member, said predetermined force beingovercome by said predetermined weight of material on said pan such thatsaid pan moves from said material-receiving position, increasing thedistance between said elements and thereby decreasing the attractiveforce between said elements so as to release said latch for movementaway from engagement with said valve memher.

5. Apparatus as defined in claim 4, further including i. pivotalmounting means for said pan comprising a beam mounted for pivotalmovement on a horizontal axis and carrying said pan, and

ii. a counterweight carried by said beam for opposing downward movementof said pan away from said material receiving position.

6. Apparatus as defined in claim for dispensing flowable solid material,wherein the inner surface of said pan is of conical configurationsloping downwardly at an angle of between about 3 and about to thehorizontal when said pan is in material-receiving position, said pantilting downwardly, for dumping material received therein, when movedfrom material-receiving position by weight on said pan.

7. Apparatus as defined in claim 5, wherein said beam includes aportion, on the side of said axis opposite to said pan, having an outerperiphery of arcuate configuration concentric with the axis of beammovement, and further including i. a roller frictionally engaging saidarcuate periphery for rotation in response to pivotal movement of saidbeam, and

ii. means for exerting a damping force on said roller to opposeoscillation of said beam incident to pivotal movement of said beam.

8. Apparatus as defined in claim 7, further including means, mountingsaid roller, for causing said roller to bear with. greater force againstsaid arcuate periphery during upward movement of said pan than duringdownward movement of said pan.

9. Apparatus as defined in claim 8, wherein said roller-mounting meanscomprises a crankshaft pivotally movable about a horizontal axis andsupporting said roller for rotation about a horizontal axis spaced fromsaid crankshaft axis, said crankshaft axis and said beam axis beingspaced apart in a common plane at a distance greater than the radius ofsaid arcuate periphery but less than the sum of said radius and thedistance between said crankshaft axis and said roller axis, said rolleraxis lying above said common plane.

10. Apparatus as defined in claim 7, wherein said damping meanscomprises at least one blade carried by said roller for rotationtherewith and so shaped that air resistance to rotation of said bladeexerts a damping force on said roller.

11. Apparatus as defined in claim 5, wherein said latch is biased bygravity away from engagement with said valve member, and wherein saidvalve member is pivotally mounted and is biased by gravity tooutletclosing position.

12. Apparatus as defined in claim 5, wherein said latch is biased bygravity away from said valve member, wherein said valve member ismounted for sliding movement between outlet-opening and outlet-closingpositions; and further including i. means for resiliently biasing saidvalve member toward outlet-closing position;

ii. a cam follower carried by said valve member; and

iii. cam means including a manually operable handle for engaging saidcam follower, upon movement of said handle, to move said valve member tooutletopening position.

13. Apparatus according to claim 4, wherein said magnetic elements areso disposed as to be spaced apart, when said pan is in saidmaterial-receiving position, along a line substantially perpendicular tothe direction of motion, and further including means, mounting at leastone of said elements for positional adjustment toward and away from theother along said line, for varying the distance between said elements,thereby to vary the magnitude of the attractive force between saidelements.

14. Apparatus according to claim 13, wherein said element-mounting meanscomprises means for threadedly mounting one of said magnetic elements onsaid latch.

15. Apparatus as defined in claim 6, wherein said angle is about 5.

16. In apparatus for dispensing flowable material, the combination of a.a pan for receiving said material;

b. a beam mounted forpivotal movement on a horizontal axis and carryingsaid pan for pivotal movement upwardly to and downwardly from ahorizontal material-receiving position in response to absence andpresence of material on said pan; and

c. a counterweight carried by said beam for opposing downward movementof said pan from said horizontal position;

wherein the improvement comprises:

d. said beam including a portion having an arcuate periphery concentricwith said beam axis, disposed on the side of said beam axis opposite tosaid pan;

e. a roller frictionally engaging said arcuate periphery for rotation inresponse to pivotal movement of said beam;

f. means, mounting said roller, for causing said roller to bear withgreater force against said arcuate periphery during upward movement ofsaid pan than during downward movement of said pan; and

g. means for exerting a damping force on said roller to opposeoscillation of said beam incident to pivotal movement of said beam.

17. In apparatus for inhibiting oscillation incident to pivotalmovement, the combination of a. a member pivotally movable in either oftwo opposite directions about a first axis;

b. said member including a portion having an arcuate periphery of givenradius concentric with said first axis;

. a roller engaging said arcuate periphery for rotation incorrespondence with movement of said member;

a crankshaft mounted for pivotal movement about a second axis parallelto said first axis and supporting said roller for rotation about a thirdaxis parallel to and spaced from said second axis, said first and secondaxes lying in a common plane and being spaced apart by a distancegreater than said radius but less than the sum of said radius and thedistance between said second and third axes, for causing said roller tobear against said arcuate periphery with greater force when said membermoves in one of said directions than when said member moves in the otherof said directions; and

. means for exerting a damping force on said roller to opposeoscillation of said member incident to movement of said member in saidone direction 18. Apparatus as defined in claim 17, wherein said dampingmeans comprises at least one blade carried by said roller for rotationtherewith and so shaped that air resistance to rotation of said bladeexerts a damping force on said roller.

19. Manually controllable apparatus for dispensing metered quantities offlowable material, comprising:

a. a container for the material having a discharge outlet;

b. a valve member for opening and closing the outlet, biased towardoutlet-closing position but movable to a position at which the outlet isopen;

'. releasable means for engaging and retaining said valve member inoutlet-opening position; and

d. means for releasing said releasable means, to permit said valvemember to close said outlet, in response to discharge of a predeterminedquantity of the material through said outlet following movement of thevalve member to outlet-opening position, said releasing means includinga pivotally mounted pan for receiving material discharged through saidoutlet and tippable to dump material received on the pan;

e. an arm connected to said valve member for movement therewith; and

f, a manually controllable valve opening member, separate from andmovable independently of said pan and said releasable means, biased to afirst position and movable therefrom to a second position g. said armhaving a portion displaceable in relation to said valve member forpermitting return movement of said valve-opening member from said secondposition to said first position in said path without displacement ofsaid valve member and regardless of the position of said valve member,so that each movement of said manually controllable member from itsfirst position to its second position, beginning when said valve memberis in its outlet-closing position, causes a single operation of saidreleasing means to discharge said predetermined quantity of material.

1. In dispensing apparatus, the combination of a. a pan for receivingmaterial to be dispensed; b. means for supporting the pan for movementto and from a material-receiving position in response to absence orpresence of weight on the pan; and c. means for retaining said pan insaid position with a force that is overcome, releasing said pan formovement, by a preselected weight of material on the pan; wherein theimprovement comprises d. said retaining means including first and secondmutually attracting magnetic elements respectively carried by said panfor movement therewith and connected to said supporting means, saidelements being spaced apart, when said pan is in said position, along aline substantially perpendicular to the direction of motion of saidfirst element such that said elements exert on each other an attractiveforce opposing movement of said pan from said position; and e. means,mounting at least one of said elements for positional adjustment towardand away from the other along said line, for varying the distancebetween said elements, thereby to vary the magnitude of saidlast-mentioned force.
 2. to release said arm to permit subsequent returnmovement of said valve member to outlet-closing position upon actuationof said releasing means; g. said arm having a portion displaceable inrelation to said valve member for permitting return movement of saidvalve-opening member from said second position to said first position insaid path without displacement of said valve member and regardless ofthe position of said valve member, so that each movement of saidmanually controllable member from its first position to its secondposition, beginning when said valve member is in its outlet-closingposition, causes a single operation of said releasing means to dischargesaid predetermined quantity of material.
 2. In dispensing apparatus, thecombination of a. a pan for receiving flowable material to be dispensed;b. means for supporting the pan for movement to and from amaterial-receiving position in response to absence or presence of weighton the pan; c. means for retaining said pan in said position with aforce that is overcome, releasing said pan for movement, by apreselected weight of material on the pan; and d. means for dischargingflowable material onto said pan when said pan is in said position,including control means for starting and stopping discharge of material;wherein the improvement comprises e. said control means including amovable control member normally urged to a position for stoppingdischarge but movable away from discharge-stopping position forpermitting discharge; and f. said retaining means including first andsecond mutually attracting magnetic elements respectively carried bysaid pan and by said control member, said elements being spaced apart bya distance which is at a finite minimum value when said pan is in saidmaterial-receiving position and said elements then exerting on eachother a predetermined attractive force simultaneously opposing movementof said pan and holding said control member away from saiddischarge-stopping position, said predetermined force being overcome bysaid predetermined weight of material on said pan such that said panmoves from said material-receiving position, increasing the distancebetween said elements and thereby decreasing the attractive forcebetween said elements so as to release said control member for movementto said discharge-stopping position.
 3. Apparatus as defined in claim 2,wherein said magnetic elements are spaced apart, when said pan is insaid material-receiving position, along a line substantiallyperpendicular to the direction of motion of said first element; andfurther including means, mounting at least one of said elements forpositional adjustment toward and away from the other along said line,for varying the distance between said elements, thereby to vary themagnitude of the attractive force between said elements.
 4. Indispensing apparatus, the combination of a. a container having adownwardly opening outlet for discharging flowable material; b. a valvemember for closing said outlet biased to outlet-closing position butdisplaceable to a position at which said outlet is open; c. a pivotedlatch for engaging and holding said valve member in outlet-openingposition, biased away from engagement with said valve member; d. a panfor receiving flowable material discharged through said outlet,pivotally movable upwardly to and downwardly from a material-receivingposition beneath said outlet in respOnse to absence and presence ofweight on the pan; and e. means for retaining said pan and latch inpositions for discharge of material through said outlet onto said pan,said retaining means holding said pan in said position with a force thatis overcome, releasing said pan for movement, by a preselected weight ofmaterial on the pan, said retaining means including first and secondmutually attracting magnetic elements respectively carried by said panand by said latch, said elements being spaced apart by a distance whichis at a finite minimum value when said pan is in said material-receivingposition and said elements then exerting on each other a predeterminedattractive force simultaneously opposing movement of said pan andholding said latch in position for engaging said valve member, saidpredetermined force being overcome by said predetermined weight ofmaterial on said pan such that said pan moves from saidmaterial-receiving position, increasing the distance between saidelements and thereby decreasing the attractive force between saidelements so as to release said latch for movement away from engagementwith said valve member.
 5. Apparatus as defined in claim 4, furtherincluding i. pivotal mounting means for said pan comprising a beammounted for pivotal movement on a horizontal axis and carrying said pan,and ii. a counterweight carried by said beam for opposing downwardmovement of said pan away from said material receiving position. 6.Apparatus as defined in claim 5 for dispensing flowable solid material,wherein the inner surface of said pan is of conical configurationsloping downwardly at an angle of between about 3* and about 10* to thehorizontal when said pan is in material-receiving position, said pantilting downwardly, for dumping material received therein, when movedfrom material-receiving position by weight on said pan.
 7. Apparatus asdefined in claim 5, wherein said beam includes a portion, on the side ofsaid axis opposite to said pan, having an outer periphery of arcuateconfiguration concentric with the axis of beam movement, and furtherincluding i. a roller frictionally engaging said arcuate periphery forrotation in response to pivotal movement of said beam, and ii. means forexerting a damping force on said roller to oppose oscillation of saidbeam incident to pivotal movement of said beam.
 8. Apparatus as definedin claim 7, further including means, mounting said roller, for causingsaid roller to bear with greater force against said arcuate peripheryduring upward movement of said pan than during downward movement of saidpan.
 9. Apparatus as defined in claim 8, wherein said roller-mountingmeans comprises a crankshaft pivotally movable about a horizontal axisand supporting said roller for rotation about a horizontal axis spacedfrom said crankshaft axis, said crankshaft axis and said beam axis beingspaced apart in a common plane at a distance greater than the radius ofsaid arcuate periphery but less than the sum of said radius and thedistance between said crankshaft axis and said roller axis, said rolleraxis lying above said common plane.
 10. Apparatus as defined in claim 7,wherein said damping means comprises at least one blade carried by saidroller for rotation therewith and so shaped that air resistance torotation of said blade exerts a damping force on said roller. 11.Apparatus as defined in claim 5, wherein said latch is biased by gravityaway from engagement with said valve member, and wherein said valvemember is pivotally mounted and is biased by gravity to outlet-closingposition.
 12. Apparatus as defined in claim 5, wherein said latch isbiased by gravity away from said valve member, wherein said valve memberis mounted for sliding movement between outlet-opening andoutlet-closing positions; and further including i. means for resilientlybiasing said valve member toward outlet-closing position; ii. a camfollower carried by said valve Member; and iii. cam means including amanually operable handle for engaging said cam follower, upon movementof said handle, to move said valve member to outlet-opening position.13. Apparatus according to claim 4, wherein said magnetic elements areso disposed as to be spaced apart, when said pan is in saidmaterial-receiving position, along a line substantially perpendicular tothe direction of motion, and further including means, mounting at leastone of said elements for positional adjustment toward and away from theother along said line, for varying the distance between said elements,thereby to vary the magnitude of the attractive force between saidelements.
 14. Apparatus according to claim 13, wherein saidelement-mounting means comprises means for threadedly mounting one ofsaid magnetic elements on said latch.
 15. Apparatus as defined in claim6, wherein said angle is about 5*.
 16. In apparatus for dispensingflowable material, the combination of a. a pan for receiving saidmaterial; b. a beam mounted for pivotal movement on a horizontal axisand carrying said pan for pivotal movement upwardly to and downwardlyfrom a horizontal material-receiving position in response to absence andpresence of material on said pan; and c. a counterweight carried by saidbeam for opposing downward movement of said pan from said horizontalposition; wherein the improvement comprises: d. said beam including aportion having an arcuate periphery concentric with said beam axis,disposed on the side of said beam axis opposite to said pan; e. a rollerfrictionally engaging said arcuate periphery for rotation in response topivotal movement of said beam; f. means, mounting said roller, forcausing said roller to bear with greater force against said arcuateperiphery during upward movement of said pan than during downwardmovement of said pan; and g. means for exerting a damping force on saidroller to oppose oscillation of said beam incident to pivotal movementof said beam.
 17. In apparatus for inhibiting oscillation incident topivotal movement, the combination of a. a member pivotally movable ineither of two opposite directions about a first axis; b. said memberincluding a portion having an arcuate periphery of given radiusconcentric with said first axis; c. a roller engaging said arcuateperiphery for rotation in correspondence with movement of said member;d. a crankshaft mounted for pivotal movement about a second axisparallel to said first axis and supporting said roller for rotationabout a third axis parallel to and spaced from said second axis, saidfirst and second axes lying in a common plane and being spaced apart bya distance greater than said radius but less than the sum of said radiusand the distance between said second and third axes, for causing saidroller to bear against said arcuate periphery with greater force whensaid member moves in one of said directions than when said member movesin the other of said directions; and e. means for exerting a dampingforce on said roller to oppose oscillation of said member incident tomovement of said member in said one direction
 18. Apparatus as definedin claim 17, wherein said damping means comprises at least one bladecarried by said roller for rotation therewith and so shaped that airresistance to rotation of said blade exerts a damping force on saidroller.
 19. Manually controllable apparatus for dispensing meteredquantities of flowable material, comprising: a. a container for thematerial having a discharge outlet; b. a valve member for opening andclosing the outlet, biased toward outlet-closing position but movable toa position at which the outlet is open; c. releasable means for engagingand retaining said valve member in outlet-opening position; and d. meansfor releasing said releasable means, to permit said valve member toclose said outlet, in response to discharge of a predetermined quantityof the material through said outlet following movement of the valvemember to outlet-opening position, said releasing means including apivotally mounted pan for receiving material discharged through saidoutlet and tippable to dump material received on the pan; e. an armconnected to said valve member for movement therewith; and f, a manuallycontrollable valve opening member, separate from and movableindependently of said pan and said releasable means, biased to a firstposition and movable therefrom to a second position along a definedpath, said manually controllable member being effective, upon eachcomplete movement from said first position to said second positioninitiated when the valve member is closed, successively: